Journal of Pure and Applied AlgebraVolume 53, Issues 1–2, August 1988, Pages 125-137Cohomology of class groups of cyclotomic fields; an application to Morse-Smale diffeomorphismsAuthor links open overlay panelRené SchoofShow moreShareCitehttps://doi.org/10.1016/0022-4049(88)90016-3Get rights and contentUnder an Elsevier user licenseopen archiveAbstractThe obstruction group SSF came up in the topological investigations of Shub and Franks. It was studied by Bass and Lenstra; the latter showed thatSSF ≅ ⊕n⩾1PicZζn,1n. In this paper the structure of SSF as an abelian group is determined. It is proved thatSSF ≅ ⊕n⩾1Z⧸/nZ confirming a conjecture of Lenstra.Previous article in issueNext article in issueRecommended articlesCited by (0)Copyright © 1988 Published by Elsevier B.V.